Windows 10 Mobile update crash

On my Lumia 925, originally sold with Windows 8.1, i installed the official Windows 10: at a certain point i made an hard reset and the phone automatically downloaded Windows 10. The hard reset was done when i was not able to install updates on the Windows 10 preview (from Windows Insider); now there were an update for the official Windows 10 ending for 107, if i remember well, but the phone was not able to complete the install. I noticed that continuously tapping on the screen, in order to avoid the phone standby, the procedure was able to end, but after the reboot the screen showed 2 gears and then a big sad smile , as this -> : – ( No way to reset hard or soft, at every reboot the gears and then after a few seconds the dreaded smile: i was already thinking to buy a new phone. But i discovered the Windows Device Recovery Tool, that after the downloading of 1,65 gb installed a working Windows 8.1 on my phone; and then using the Windows Phone Developer Registration 8.1 (installed with Windows Phone SDK 8.1) i re-registered the device in order to publish on it my apps developed with Visual Studio 2013. Thanks to Google sync i lost nothing of interest, but anyway i will be suspicious about updating the 925 to Windows 10..